:root {
  color-scheme: light;
  --bg: #F7F8F5;
  --surface: #FFFFFF;
  --surface-soft: #FAFBF8;
  --text-primary: #202124;
  --text-secondary: #5F6368;
  --border: #DADCE0;
  --primary: #1E7A5F;
  --primary-dark: #145B46;
  --primary-soft: #E6F3EE;
  --accent-blue: #2F6FDB;
  --accent-blue-soft: #E8F0FE;
  --warning: #F4B400;
  --warning-soft: #FFF8DF;
  --error: #D93025;
  --error-soft: #FCE8E6;
  --code-bg: #F1F3F4;
  --shadow: 0 12px 28px rgba(32, 33, 36, 0.08);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text-primary);
  font-family: Pretendard, system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
  font-size: 17px;
  line-height: 1.55;
}

a {
  color: inherit;
}

button,
a {
  -webkit-tap-highlight-color: transparent;
}

button {
  font: inherit;
}

.app-shell {
  display: grid;
  grid-template-columns: 248px minmax(0, 1fr);
  gap: 18px;
  min-height: 100vh;
  padding: 18px;
}

.sidebar,
.screen-panel,
.card,
.template-box,
.flow-card {
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--surface);
}

.sidebar {
  position: sticky;
  top: 18px;
  display: grid;
  grid-template-rows: auto auto 1fr auto;
  gap: 18px;
  align-self: start;
  min-height: calc(100vh - 36px);
  max-height: calc(100vh - 36px);
  overflow: auto;
  padding: 16px;
}

.brand {
  display: grid;
  gap: 4px;
  color: var(--text-primary);
  text-decoration: none;
}

.brand strong {
  font-size: 20px;
  line-height: 1.2;
}

.brand span {
  color: var(--text-secondary);
  font-size: 13px;
  font-weight: 800;
}

.screen-nav {
  display: grid;
  gap: 6px;
}

.nav-link {
  display: grid;
  gap: 2px;
  min-height: 54px;
  padding: 9px 10px;
  border: 1px solid transparent;
  border-radius: 7px;
  color: var(--text-primary);
  text-decoration: none;
}

.nav-link span {
  color: var(--text-secondary);
  font-size: 12px;
  font-weight: 900;
}

.nav-link strong {
  font-size: 15px;
  line-height: 1.25;
}

.nav-link:hover,
.nav-link:focus-visible {
  border-color: var(--border);
  outline: none;
}

.nav-link.is-active {
  border-color: var(--primary);
  background: var(--primary-soft);
}

.tool-panel {
  display: grid;
  gap: 8px;
  padding-top: 14px;
  border-top: 1px solid var(--border);
}

.tool-label {
  color: var(--text-secondary);
  font-size: 12px;
  font-weight: 900;
}

.tool-link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 44px;
  padding: 10px 12px;
  border: 1px solid var(--primary);
  border-radius: 7px;
  background: var(--primary);
  color: #fff;
  font-size: 15px;
  font-weight: 900;
  text-decoration: none;
}

.tool-link.secondary {
  border-color: var(--border);
  background: var(--surface);
  color: var(--text-primary);
}

.tool-link span {
  font-size: 18px;
  line-height: 1;
}

.tool-link:hover,
.tool-link:focus-visible {
  outline: 3px solid var(--primary-soft);
  outline-offset: 2px;
}

.main-area {
  display: grid;
  min-width: 0;
  align-content: start;
  gap: 14px;
}

.screen-panel {
  display: flex;
  flex-direction: column;
  min-height: calc(100vh - 36px);
  padding: clamp(22px, 3vw, 34px);
  box-shadow: var(--shadow);
}

.screen-kicker,
.label,
.meta {
  display: inline-flex;
  width: fit-content;
  min-height: 29px;
  align-items: center;
  padding: 0 9px;
  border-radius: 999px;
  font-size: 13px;
  font-weight: 900;
}

.screen-kicker,
.label {
  border: 1px solid var(--border);
  background: var(--primary-soft);
  color: var(--primary);
}

.meta {
  background: var(--accent-blue-soft);
  color: var(--accent-blue);
}

.meta.pending {
  background: var(--warning-soft);
  color: #7A5600;
}

h1,
h2,
h3,
p,
ul,
ol {
  margin-top: 0;
}

h1 {
  max-width: 980px;
  margin: 12px 0 12px;
  font-size: clamp(34px, 5vw, 52px);
  line-height: 1.12;
  letter-spacing: 0;
  word-break: keep-all;
}

h2 {
  margin-bottom: 10px;
  font-size: clamp(25px, 3vw, 34px);
  line-height: 1.2;
  letter-spacing: 0;
}

h3 {
  margin-bottom: 8px;
  font-size: 20px;
  line-height: 1.25;
  letter-spacing: 0;
}

p,
li {
  color: var(--text-secondary);
}

.lead {
  max-width: 860px;
  margin-bottom: 22px;
  color: var(--text-primary);
  font-size: 21px;
  font-weight: 760;
  word-break: keep-all;
}

.lead.wide {
  max-width: 1180px;
}

.start-cover {
  display: grid;
  min-height: calc(100vh - 104px);
  align-content: start;
  gap: clamp(30px, 4vw, 52px);
}

.start-hero {
  display: grid;
  gap: 18px;
  max-width: 1160px;
}

.start-title {
  margin: 0;
  max-width: 1080px;
  font-size: clamp(42px, 5.8vw, 82px);
  font-weight: 950;
  line-height: 1.08;
  letter-spacing: 0;
  word-break: keep-all;
}

.start-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.start-reason {
  display: grid;
  gap: 18px;
  padding-top: clamp(22px, 3vw, 36px);
  border-top: 1px dashed var(--border);
}

.start-reason h2 {
  margin: 12px 0 0;
}

.start-reason-card {
  min-height: 190px;
  background: var(--surface-soft);
}

.start-reason-card h3 {
  font-size: clamp(20px, 1.8vw, 26px);
}

.start-reason-card p {
  color: var(--text-primary);
  font-size: 16px;
  font-weight: 650;
  word-break: keep-all;
}

.grid {
  display: grid;
  gap: 12px;
}

.action-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
  margin-top: 24px;
}

.two-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.three-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.class-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.card {
  display: grid;
  gap: 8px;
  align-content: start;
  min-height: 116px;
  padding: 16px;
  color: inherit;
  text-decoration: none;
}

.card strong {
  color: var(--text-primary);
}

.card p {
  margin-bottom: 0;
  font-size: 15px;
}

.game-card {
  min-height: 168px;
}

.game-card-top {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: flex-start;
  gap: 8px;
}

.team-badge,
.game-status {
  display: inline-flex;
  width: fit-content;
  min-height: 28px;
  align-items: center;
  padding: 0 9px;
  border-radius: 999px;
  font-size: 13px;
  font-weight: 900;
}

.team-badge {
  background: var(--accent-blue-soft);
  color: var(--accent-blue);
}

.game-title {
  color: var(--text-primary);
  font-size: 25px;
  line-height: 1.25;
}

.game-intro {
  margin: 0;
  color: var(--text-secondary);
  font-size: 16px;
  font-weight: 720;
}

.game-status {
  background: var(--primary-soft);
  color: var(--primary);
}

.game-status.pending {
  background: var(--warning-soft);
  color: #7A5600;
}

a.card:hover,
a.card:focus-visible {
  border-color: var(--primary);
  outline: 3px solid var(--primary-soft);
  outline-offset: 2px;
}

.button,
.plain-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 42px;
  padding: 0 15px;
  border-radius: 7px;
  font-size: 15px;
  font-weight: 850;
  text-decoration: none;
  white-space: nowrap;
  cursor: pointer;
}

.button {
  border: 1px solid var(--primary);
  background: var(--primary);
  color: #fff;
}

.button.secondary,
.plain-button {
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-primary);
}

.button.info {
  border-color: var(--accent-blue);
  background: var(--accent-blue);
  color: #fff;
}

.button:hover,
.button:focus-visible,
.plain-button:hover,
.plain-button:focus-visible {
  outline: 3px solid var(--primary-soft);
  outline-offset: 2px;
}

.info-box,
.warning-box,
.error-box {
  margin-top: 14px;
  padding: 15px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--surface-soft);
}

.warning-box {
  background: var(--warning-soft);
}

.error-box {
  border-color: #F3B8B2;
  background: var(--error-soft);
}

.info-box strong,
.warning-box strong,
.error-box strong {
  display: block;
  margin-bottom: 4px;
  color: var(--text-primary);
}

.activity-timer {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  margin: 0 0 clamp(24px, 2.4vw, 32px);
  padding: 14px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--surface-soft);
}

.activity-timer.is-running {
  align-items: center;
  padding: clamp(20px, 3vw, 34px);
  border-color: var(--primary);
  background: var(--primary-soft);
}

.timer-status {
  display: grid;
  gap: 2px;
}

.timer-status strong {
  color: var(--text-primary);
  font-size: 15px;
}

.timer-status span {
  color: var(--text-secondary);
  font-size: 13px;
  font-weight: 800;
}

.timer-display {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 34px;
  font-weight: 900;
  line-height: 1;
}

.activity-timer.is-running .timer-display {
  font-size: clamp(72px, 12vw, 156px);
  letter-spacing: 0;
}

.timer-controls {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.flow-card {
  display: grid;
  align-content: start;
  gap: clamp(15px, 2vw, 24px);
  min-height: calc(100vh - 104px);
  padding: clamp(22px, 3.6vw, 50px);
}

.flow-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
}

.step-label {
  color: var(--primary);
  font-size: 18px;
  font-weight: 900;
}

.slide-controls {
  display: flex;
  gap: 8px;
}

.slide-button {
  display: inline-flex;
  width: 42px;
  height: 42px;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--border);
  border-radius: 50%;
  background: var(--surface);
  color: var(--text-primary);
  font-size: 26px;
  font-weight: 900;
  line-height: 1;
  cursor: pointer;
}

.slide-button:hover,
.slide-button:focus-visible {
  border-color: var(--primary);
  outline: 3px solid var(--primary-soft);
  outline-offset: 2px;
}

.slide-button:disabled {
  opacity: 0.35;
  cursor: default;
}

.flow-card h3 {
  max-width: 1120px;
  margin-bottom: 0;
  font-size: clamp(34px, 4.4vw, 64px);
  line-height: 1.14;
  overflow-wrap: break-word;
  text-wrap: balance;
  word-break: keep-all;
}

.flow-body {
  display: grid;
  gap: clamp(14px, 1.8vw, 24px);
  max-width: 1120px;
}

.flow-copy,
.flow-callout {
  color: var(--text-primary);
  font-size: clamp(18px, 1.55vw, 24px);
  font-weight: 650;
  overflow-wrap: break-word;
  text-wrap: pretty;
  word-break: keep-all;
}

.flow-copy p,
.flow-callout p {
  margin-bottom: 10px;
}

.flow-copy p:last-child,
.flow-copy ul:last-child,
.flow-callout p:last-child {
  margin-bottom: 0;
}

.practice-image-frame {
  display: grid;
  gap: 10px;
  max-width: 1120px;
  margin: 0;
}

.practice-image-frame img {
  display: block;
  width: 100%;
  max-height: 62vh;
  object-fit: contain;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--surface-soft);
}

.practice-image-frame figcaption {
  color: var(--text-secondary);
  font-size: 14px;
  font-weight: 800;
}

.missing-image {
  display: none;
  min-height: 220px;
  align-items: center;
  justify-content: center;
  padding: 24px;
  border: 1px dashed var(--border);
  border-radius: 8px;
  background: var(--surface-soft);
  color: var(--text-secondary);
  font-size: 16px;
  font-weight: 800;
  text-align: center;
}

.practice-image-frame.is-missing .missing-image {
  display: flex;
}

.slide-link-card {
  max-width: 720px;
}

.flow-callout {
  padding-top: clamp(14px, 1.8vw, 24px);
  border-top: 1px solid var(--border);
}

.flow-callout strong {
  display: block;
  margin-bottom: 8px;
  color: var(--text-primary);
  font-size: clamp(18px, 1.6vw, 24px);
}

.diagram-flow,
.diagram-trio,
.diagram-stack,
.diagram-loop {
  display: grid;
  gap: 10px;
  max-width: 1120px;
}

.diagram-flow {
  grid-template-columns: 1fr auto 1fr auto 1fr;
  align-items: center;
}

.diagram-trio,
.diagram-stack {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.diagram-loop {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.diagram-card {
  min-height: 92px;
  padding: 16px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--surface-soft);
}

.diagram-card strong {
  display: block;
  margin-bottom: 6px;
  color: var(--primary-dark);
  font-size: clamp(17px, 1.4vw, 22px);
  line-height: 1.2;
}

.diagram-card span {
  display: block;
  color: var(--text-secondary);
  font-size: clamp(14px, 1.1vw, 18px);
  line-height: 1.38;
  word-break: keep-all;
}

.diagram-arrow {
  color: var(--primary);
  font-size: 28px;
  font-weight: 900;
  line-height: 1;
}

.diagram-card.is-blue {
  background: var(--accent-blue-soft);
}

.diagram-card.is-yellow {
  background: var(--warning-soft);
}

.diagram-card.is-green {
  background: var(--primary-soft);
}

.activity-row {
  display: grid;
  grid-template-columns: 46px minmax(0, 1fr);
  gap: 12px;
  align-items: start;
  padding: 14px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--surface);
}

.activity-row .number {
  display: inline-flex;
  width: 34px;
  height: 34px;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: var(--primary-soft);
  color: var(--primary);
  font-weight: 900;
}

.chip-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 0;
}

.chip {
  display: inline-flex;
  min-height: 38px;
  align-items: center;
  padding: 0 14px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--surface-soft);
  color: var(--text-primary);
  font-size: 14px;
  font-weight: 800;
}

.template-box {
  overflow: hidden;
  margin-top: 14px;
}

.template-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 12px 14px;
  border-bottom: 1px solid var(--border);
  background: var(--surface);
}

pre {
  overflow-x: auto;
  margin: 0;
  padding: 18px;
  background: var(--code-bg);
  color: var(--text-primary);
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 14px;
  line-height: 1.6;
  white-space: pre-wrap;
}

.screen-section {
  margin-top: clamp(28px, 3vw, 38px);
}

.screen-section h2 {
  margin-bottom: 16px;
}

.screen-panel > .grid:not(.action-grid) {
  margin-top: 18px;
}

.warning-box + .grid,
.info-box + .grid {
  margin-top: 18px;
}

.activity-timer + .screen-section,
.activity-timer + .grid:not(.action-grid),
.activity-timer + .warning-box {
  margin-top: 0;
}

.quiet-link {
  margin-top: clamp(28px, 3vw, 38px);
  padding-top: 18px;
  border-top: 1px solid var(--border);
}

.quiet-link a {
  color: var(--text-secondary);
  font-size: 15px;
  font-weight: 850;
  text-decoration: none;
}

.quiet-link a:hover,
.quiet-link a:focus-visible {
  color: var(--primary);
  outline: none;
  text-decoration: underline;
  text-underline-offset: 3px;
}

[aria-disabled="true"] {
  cursor: not-allowed;
}

@media (max-width: 1180px) {
  .app-shell {
    grid-template-columns: 220px minmax(0, 1fr);
  }

  .action-grid,
  .class-grid,
  .three-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 1024px) {
  .app-shell {
    grid-template-columns: 1fr;
  }

  .sidebar {
    position: sticky;
    top: 0;
    z-index: 10;
    min-height: auto;
    max-height: none;
  }

  .screen-nav {
    display: flex;
    overflow-x: auto;
    padding-bottom: 4px;
  }

  .nav-link {
    min-width: 168px;
  }

  .screen-panel {
    min-height: auto;
  }
}

@media (max-width: 640px) {
  body {
    font-size: 16px;
  }

  .app-shell {
    padding: 10px;
  }

  .sidebar,
  .screen-panel {
    padding: 14px;
  }

  .action-grid,
  .class-grid,
  .two-grid,
  .three-grid {
    grid-template-columns: 1fr;
  }

  .button,
  .plain-button {
    width: 100%;
    white-space: normal;
  }

  .flow-card {
    min-height: auto;
    gap: 18px;
    padding: 20px;
  }

  .flow-card h3 {
    font-size: 30px;
    line-height: 1.18;
  }

  .flow-top {
    align-items: flex-start;
    flex-direction: column;
  }

  .start-cover {
    min-height: auto;
    align-content: center;
  }

  .start-title {
    font-size: clamp(34px, 10vw, 56px);
  }

  .diagram-flow,
  .diagram-trio,
  .diagram-stack,
  .diagram-loop {
    grid-template-columns: 1fr;
  }

  .diagram-arrow {
    display: none;
  }

  .activity-timer,
  .timer-controls {
    align-items: stretch;
    flex-direction: column;
  }
}